Why do some of my home-canned foods, like green beans, corn, pears and some
other fruit I can, sometimes change color?

In general, oxidation may cause foods to darken at the tops of jars. Oxidation is
from air in the jars or too little heating or processing to destroy enzymes. Overprocessing may cause discolored foods throughout the containers.
Here are some more specific color changes and their causes:

Pink
and blue colors sometimes seen in canned pears, apples, and peaches
are caused by chemical changes in the coloring matter of the fruit.

Brown, black, and gray colors may be caused by iron and
copper from cooking utensils (or from water in some localities) in some foods. When canned corn turns brown,
the discoloring may be due to the variety of the corn, to stage of ripeness,
to overprocessing, or to copper or iron pans. Packing liquid may dissolve
coloring materials from the foods. To help avoid this, use soft water and to
avoid using brass, copper, iron, aluminum, zinc, or chipped enamelware. Also
avoid using utensils that have worn surfaces. If the shiny silvery
appearance is worn off, the tin metal underneath may be exposed. The water
around green beans often may have a reddish brown tint to it. Again, that's
not that unusual and may be due to iron or possibly overprocessing. Of
course, if the lid bulges then discard the contents.

Darkening of foods at the tops of jars may be caused by oxidation due to
air in the jars or by too little heating or processing to destroy enzymes.This
is common in jams, jellies and fruit. Often just adding 1 tablespoon
of lemon juice, or sprinkling Fruit Fresh or finely ground vitamin C tablets
will help prevent this.

Overprocessing may cause discoloration of foods throughout the containers.
Finally, the use of plain tin cans will cause some
foods to lose color.

Reference: U.S.D.A. 1976. Home Canning of Fruits and Vegetables. Home and
Garden Bulletin No. 8. (Issued February 1965, Slightly revised May 1976).
United States Department of Agriculture, Washington, D.C.

Is it safe to eat discolored canned foods?

The color changes noted above do not mean the food is unsafe to eat.
However, spoilage may also cause color changes. Any canned food that has an
unusual color should be examined carefully before use.

Reference:
U.S.D.A. 1976. Home Canning of Fruits and Vegetables. Home and Garden
Bulletin No. 8. (Issued February 1965, Slightly revised May 1976). United
States Department of Agriculture, Washington, D.C.

Home canning is both an art and a science. Safety and quality are some of the
reasons it is important to follow recommended recipes and procedures for home
canning. That is the science. The art comes from the experience of what is
"finger tight", when is the product packed too full or too loose or determining
just the right ripeness.

Canning books

The All New Ball Book Of Canning And Preserving: Over 350 of the Best Canned, Jammed, Pickled, and Preserved Recipes Paperback - May 31, 2016

This is THE book on canning! My grandmother used this book when I
was a child. It tells you in simple instructions how to can almost
anything; complete with recipes for jam, jellies, pickles, sauces, canning
vegetables, meats, etc. If it can be canned, this book likely tells
you how! Click on the link below for more information and / or to buy (no
obligation to buy)

Home Canning Kits

This is the same type of standard canner that my grandmother used to
make everything from applesauce to jams and jellies to tomato and
spaghetti sauce. This complete kit includes everything you need and lasts
for years: the canner, jar rack, jar grabber tongs, lid lifting wand, a
plastic funnel, labels, bubble freer, and the bible of canning, the Ball
Blue Book. It's much cheaper than buying the items separately. You'll
never need anything else except jars & lids (and the jars are reusable)!
There is also a simple kit with just the canner and rack, and a pressure canner, if you want to do vegetables (other than tomatoes). To see
more canners, of different styles, makes and prices, click here!

This is the same type of standard canner that my grandmother used to make everything from applesauce to jams and jellies to tomato and spaghetti sauce. This complete kit includes everything you need and lasts for years: the canner, jar rack, jar grabber tongs, lid lifting wand, a plastic funnel, labels, bubble freer. It's much cheaper than buying the items separately. You'll never need anything else except jars & lids (and the jars are reusable)! There is also a simple kit with just the canner and rack, and a pressure canner, if you want to do vegetables (other than tomatoes). To see
more canners, of different styles, makes and prices, click here!
Don't forget the Ball Blue Book!

Lids, Rings, Jars, mixes, pectin, etc.

Need lids, rings and replacement jars? Or pectin to make jam,
spaghetti sauce or salsa mix or pickle mixes? Get them all here, and
usually at lower prices than your local store!

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